Method of and apparatus for making paper, boxboard, and the like



F. B. WELLS June 18, 19299 METHOD OF AND APPARATUS FOR MAKING PAPER, BOXBOARD, AND THE LIKE Filed June 28,

Patented June 18, 1929.

UNITED STATES PATENT OFFICE.

FRED B. WELLS, OF RITTMAN, OHIO, ASSIGNOR TO THE OHIO BOXBOARD COMPANY, OF CLEVELAND, OHIO, A CORPORATION OF OHIO.

METHOD OF AND APPARATUS FOR MAKING PAPER, BOXIBOARD, AND THE LIKE.

Application filed June 28,

This invention relates to a method of and apparatus for producing amoisture-proof and grease-proof paper, boxboard, or the like of the type described in the copending application of John J. Gannon, Louis/IV. Mable and Fred B. Wells, for patent for paper, filed April 6, 1925,'Serial No. 21,222 (now Patent No. 1,606,163, granted November '9, 1926).

In the invention of the application for patent above mentioned, the paper produced comprises essentially a filler of requisite thickness provided on one sidewith a layer of a pergameneous material vforming an inte'gral part'of the paper, and upon the other side with a back or liner of apaper stockot' higher grade and better color than the filler. I have found it desirable to prodi'icator some uses, a paper or boxboard which" possesses to a great degree the moisture and grease-proof qualities of thepaperproduced by the invention of the application mentioned, and I have found that such a paper or boxboard may be produced by providing one side of the paper or boxboard with a multiple layer of pergameneous material, this multiple layer producing in effect, in the finished product, an integral layer and an integral part of the paper, but possessing to a greater de gree, due to its greater thickness, the grease proof or moisture-proof or both grease-proof and moisture-proof qualities desired, By the method and apparatus hereinafter described, I have been able not only to produce upon one side of the paper the integral layer of pergameneous material of multiple thickness described, but to produce also upon the other side of the paper a layer of pergameneous material.

The pergameneous material hereinabove referred to is composed of pure sulphite pulp stock Worked in a beater having a stone roll which, in its operation .upon the stock, crushesthe fibers of the sulphite pul instead of cutting them, as distinguished From the operation of the ordinary beater having a roll with steel fly bars. This crushing of the fibers of the stock, hydration of same incident to the beating action, and the mechanical working up of the stock by the stone roll, so breaks up and macerates the sulphite pulp that it forms a grease-proof product. This operation, and the stock used (sulphite pulp) are the same as are employed in the manufacture of one well-known type of pergameneous paper which is generally used for 1926. Serial No. 119,069.

the formation of containers for-salted peathe texture of this material, particularly -when laid in a web, is such that water will not pass through it. The same difliculty arisesjwhere' it is desired, as in the case of the present invention, to apply layers of pergameneous material one upon another, for

- ifsome provision is not made for removing or driving off the excess of moisture carried by the first layer of pergameneous material deposited, this layer will be crushed by the next layer deposited, water will be trapped between the two layers, and they will not adhere to each other as is necessary to produce a perfect finished product.

When the filler material is deposited in successive layers upon the pergameneous material thus formed the difficulty ust described in freeing the web of excess moisture or water does not arise, for the reason that the stock of which the filler material is composed is of such a nature that water may be easily expressed from it in a direction away from the pergameneous material.

If, as hereinbefore pointed out, it is desired to provide a back or liner of pergameneous material, then some means must be provided for carrying ofi the water from this liner also. All of the'requirements for producing the paper or boi'cboard described are met in the method and apparatus of my present invention. 7

The invention consists in a method of making paper, boxboard and the like, comprising depositing a plurality of layers of pergameneous material and withdrawing from each layor deposited, except the final layer, the excess moisture which the material contains, depositing upon the multiple layer of pergameneous material thus deposited a layer, usually of multiple form, of filler material, and applying thereto a back or liner of pergameneous material or not, as desired, and if of pergameneous material, carrylng off excess moisture therefrom, to produce a finished paper or boxboard of which all of the layers form an integral part. And the 1nvention consists further in the apparatus whereby this method may be carried out, as I will proceed now to explain and finally claim.

In the accompanying drawings illustrating the invention, in the several figures of which like parts are similarly designated, Figure 1 is a semi-diagrammatic side eleva tion of a portion of a paper making machine or board mill of the cylinder type, adapted for. the production of paper or boxboard in accordance with my invention. Fig. 2 is a side view of a suction box suited to the purposes of my invention. Fig- 31s a bot-tom plan view of the suction box. F1g. 4 1s a section of the suction box taken 011 the line 14 of Fi 3.

Referring particularly to Fig. 1 of the drawings, it will be seen that I show a portion of a board machine or mill having paper stock vats 1, 2, 3, 4, 5 and 6 in each of which rotates a cylinder 7 by which the stock contained in its respective vat is depositedupon the bottom felt 8 of the machine in the usual manner. After all of the cylinders which are being used have deposited their layer of stock upon the felt, the felt travels to the end of the machine, where it passes around the roller 9, thus bringing the web of deposited paper stock upon the upper side. The felt travels in this osition to the point 10 where it is met by t e top felt 11. and the web of paper or board thus passes along with and between the bottom and top felts, and is protected by them, in the usual manner, until it is dried. Thus far the machine or mill is the same in construction and operation as the mill for producing ordinary boxboard.

As hereinbefore pointed out, when it is desired to provide the boxboard or paper with an integral coating of grease-proof pergameneous materials in a multiple of successive layers, for example two layers, as deposited by two successive cylinders of the machine, it becomes necessary to withdraw the Water from the first layer deposited before deposit: ing the second layer. For this purpose, supposing that the vats 1 and 2 contain pergameneous material and the felt 8 is traveling in the direction of the arrows, I mount adjacent to the cylinder 7 of vat 1, and between it and the cylinder of vat 2, a suction box 12 supported upside down as compared with the ordinary mounting of suction boxes, and in contact with the top surface of the felt 8.

This suction box, particularly illustrated in Figs. 2, 3 and 4 comprises an elongated closed casing preferably of greater width than height, and of greater length than the width of the felt 8, and provided upon its plying the suction first to the center of the felt as the felt travels under the suction box, and then gradually spreading the sucking effect of the suction box laterally across the felt from the center. This will have a tendency to spreadthe felt laterally and prevent the formation of wrinkles in it and in the web of paper stock carried upon'its under surface. Moreover, by so applying the suction, the weft of the felt is subjected to less strain because a large number of weft threads are influenced at the sametime and,therefore, breaking of the felt is rendered most unlikely. A further object in forming the slit-13 in this manner is that inasmuch as these suction. boxes are usually constructed of wood, this arrangement of the slit diagonally of the grain of the wood enhances the strength of the bottom of the box. I

Suction is applied by means of a pipe 1" connected at 18 a11d19 with the interior of the box through one of its sides, and in order to evenly distribute the effect of the suction within the box, I provide a baflie 20 adjacent to the slit 13.

As will be seen, the connections 18 and 19 are substantially in line with the bottom of the box, thereby making it possible to maintain the box free of water at all times.

In forming the paper or boxboar-d of my invention, with the apparatus described, as hereinbefore stated, the vats 1 and are filled with the pergameneous grease-proof stock. Vats 3, 4 and 5 are filled with filler stock, and vat (3 is filled with liner or back stock, or if it is desired to provide a liner or back of the pergameneous material this last vat is filled with the pergameneous grease-proof stock.

\Vith suction on the suction box 12 and the vats filled as described, starting of the machine'or mill will cause the felt 8 to be fed in the direction of the arrows, thus driving the cylinders 7. The cylinder of vat 1 will lift from the vat and deposit upon the felt during its travel a layer of pergameneous material, and as this layer passes along with the felt under the suction box 12, the water will be withdrawn from the material through the felt and will be carried away through the pipe 17. This layer of material having been thus freed of its excess water the layer of grease-proof material deposited upon it by the successive action of the cylinder 7 of vat 2 will adhere to it without crushing and without blows. The filler material deposited in successive layers by the'cylinders of vats 3, 4 and 5 upon the thus formed web of grease-proof material will contain an excess of water, as will also the second layer of grease-proof material deposited, but all of this water may be removed by the usual waterremoving devices of the machine in a direction away from the pergameneous material.

If the liner or back to be deposited by the cylinder 7 of vat 6 is of the ordinary type of paper stock, operation of the suction box 21 arranged between vats 5 and 6 is not necessary. If, however, it is desired to deposit a liner or back of grease-proof material, this suction box 21, which is similar in all respects to the suction box 12, must be operated for the purpose of making certain the removal of all excess water from the already formed web before the grease-proof liner is deposited by the cylinder of vat 6.

After the web of paper or board is thus formed, it is squeezed, dried and calendered by the machine'in the ordinary manner.

It will thus be seen that I have devised a method of and means for providing paper or boxboard with a heavy impervious multiple-layer coating of grease-proof .material which forms in the finished product an integral part of the paper or board and which is uniform in its texture and appearance throughout the web ofpaper or board and free from blows and imperfections.

Moreover, it will be seen that by my invention I may produce a paper or boxboard provided with a coating of grease-proof material upon both of its faces, a result which, so far as I am aware, has never heretofore been accomplished, due tothe fact that it was impossible to effect/adhesion of the grease-proof stock to the filler stock during the paper or board forming operation. I

\ I have'described a specific method and apparatus for providing a grease-proof coating composed of two layers of pergameneous material,-bnt it is possible to multiply the layers by using a suction box after depositing each of such layers so as to withdraw the excess water.

Various changes in the method and apparatus are anticipated as within the spirit of the invention and the'scope of the following claims I What I claim is 1. A method of forming paper, boxboard and the like provided with alstratum composed of a plurality of intimately adhering layers of'pergameneous material, which consists in depositing a layer of pergameneous material, withdrawing excess water, therefrom, depositing upon the thus treated layer another layer of pergameneous material, depositing upon this doublelayer a plurality of layers of filler material sufiicient to'provide a body ofrequisite thickness, driving oil the excess water from the second layer of pergameneous. material and from the filler mateusual manner to form a finished product.

positing upon this douhle layer a plurality of layers of filler material suflicient to provide a body of requisite thickness, driving off the excess water from the second layer of pergameneous material and from the filler material, depositing upon the thus treated web a layer of back material, and thereafter treating the web in the usual manner to form a finished product. p

3. A method of forming paper, boxboard and the like provided with a stratum composedof a plurality of intimately adhering layers of pergameneous material, which consists in depositing a layer'of pergameneous material, withdrawing excess water therefrom, depositing upon the thus treated layer another layer of pergameneous material, depositing upon this double layer a plurality of layers of filler material sufiicient to provide a body of requisite thickness, driving oil the excess water from the second layer of pergameneous material and from the filler materialin a direction away from the pergameneous material, and thereafter treating the Web in the usual manner to form a finished product.

4. A method of forming paper, boxboard and the like provided with a stratum composed of a plurality of intimately adhering layers of pergameneous material, which consists indepositing a layer of pergameneous material, withdrawing excess water there-- from, depositin upon the thus treated layer another layer 0? pergameneous material, depositing upon this double layer a plurality of layers of filler material suflicient to provide a body of requisite thickness, driving off the excess water from the second layer of pergameneous material and from the filler material through the filler material, and thereafter treating the web in the usual manner to form a finished product.

--5. A method of forming paper, boxboard and the like provided with a stratum com posed of a plurality of intimately adhering layers of pergameneous material, which consists in depositing a layer of pergameneous material, withdrawing excess water .therefrom, depositing upon the thus treated layer another layer of pergameneous material, de-

of layers of filler material sufiicicnt to provide a body of requisite thickness, driving off the excess water from the second layer of pergameneous materialand from the filler material through the filler material, de ositing upon the thus treated web a layer 0 back material, and thereafter treating the web in the usual manner to form a finished product.

6. Apparatus for forming paper, boxboard and the like provided with a stratum composed of a plurality of intimately adhering layers of pergameneous material, comprising the Combination with a paper-making machine having a felt and a plurality of cylin- Y Y travel of the felt.

ders cooperating therewith for depositing the layers of pergameneous material upon the felt in superposition, of a suction-box interposed between the points of application of the per gameneous material to said felt by two of said 0 linders and cooperatively arran ed relatively to the opposite side of the elt from that upon which the pergameneous material is deposited, for drawing off excess water through said felt from one layer of said material before another layer of same is deposited thereon.

7. A suction box for paper-making machines having its face which is arranged in cooperative relation to the felt of the machine provided with a continuous suction slot diverging from the lateral center of said face towards the ends thereof in the direction of 8. A-suction box for paper-making machines having its face which is' arranged in cooperative relation to thefelt of the machine provided with a suction slot diverging continuously and angularly from the lateral center of said face towards the ends thereof in the direction of travel of the felt.

9. A suctionbox for paper-making ma chines having its face which is arranged in cooperative relation to the felt of themachine provided with a plurality of suctionslots the leading one of which diverges angularly in a single continuous line from its center toward its ends in the direction of travel of the felt; whereby the effect of the suction is so distributed from the longitudinal center of the .felt toward its lateral edges as to have a lateral spreading efl'ect upon the felt and prevent the formation of wrinkles therein.

10. A suction box for paper-making machines havingits face which is arranged in cooperative relation to the felt of the machine provided with a plurality of suction slots, a suction pipe connected with the interior of said box, and abaflle arranged between said slots and the end of said pipe, whereby suc- 1 tion is evenly distributed to the plurality of slots.

, In testimony whereofI have hereunto set as my hand this 25th day of June, A. D. 1926. FRED B." WELLS. 

